Objects may be stored and/or transported in containers, for example, to organize or improve the ease of handling the objects. For example, freight may be placed in containers for storage and/or later shipment via aircraft, trucks, boats, and/or trains. In the air freight industry, for example, freight may be transported in the bellies of passenger aircraft or in both the bellies and on main decks of freighter aircraft. Containers, generically referred to as Unit Load Devices (ULDs), may be used to contain freight for air transport. Over time, ULDs having differing sizes and shapes have been standardized and developed, both for belly and main deck application for use in various aircraft. Descriptions and specifications for ULDs may be found in documents, such as, for example, the National Aerospace Standard (NAS) 3610 and the International Air Transport Association (IATA) ULD Technical Manual.
Examples of freight placed in containers may include objects such as cardboards, woods, fabrics, packing materials, paper, and other carbon based materials, which are defined as Class A materials by the Federal Aviation Administration (FAA). Since such containers may be transported via aircraft and may be loaded into the belly or onto the main deck of an aircraft cabin, a flight crew of the aircraft may not have access to the containers, for example, once the aircraft is fully loaded and ready for flight. As a result, if a fire were to occur in a container located in the aircraft cabin, the flight crew might not have access to the container experiencing the fire, thereby preventing them from attempting to control or extinguish the fire with a hand-held fire extinguisher.
Such a fire may present serious risks, in particular, if the aircraft is airborne and a great distance from an airport suitable for making an emergency landing, such as, for example, when an aircraft is traveling over a large body of water. Such a fire may result in the loss of the flight crew and/or passengers and the aircraft.
Tests conducted by the FAA and the aviation industry have determined that a cargo fire associated with Class A materials, once ignited, may smolder and burn slowly in a container (e.g., a ULD) for an extended period of time, for example, as long as thirty minutes or more. But once the average temperature of the ULD reaches 200 degrees Fahrenheit (F.), a fire normally accelerates rapidly, often reaching 1,000 degrees F. in less than sixty seconds. Thereafter, temperatures resulting in burn-through or failure of the container walls and/or ceiling are frequently reached, and the conflagration may quickly spread to adjacent ULDs, possibly igniting them, as well.
Furthermore, some FAA-approved containers include Lexan® walls, which may pose a particularly serious problem. In particular, at very high temperatures, Lexan® will soften and may outgas, causing a flashover fire, which may greatly add to the spread of the fire. Aircraft container bases, on the other hand, are relatively thick for structural reasons, and burn-through of container bases is not considered likely. In addition, aircraft container bases may be formed from aluminum, which transfers heat well, and the aircraft containers are sometimes located on a conveyor system, including rollers or ball transfer units, which permits a cooling flow of air underneath the containers that may serve to carry heat away from the containers.
Various active fire suppression schemes for belly and main deck container fires have been implemented in the air cargo industry. Water misting and Halon® flooding, for example, are two representative examples of conventional technologies used to contain fires in aircraft cabins. Most, if not all, active suppression schemes, however, require the delivery of a suppressant agent to the container experiencing a fire. As a result, some such schemes are heavy and complex, which are not typically desirable characteristics for an aircraft fire suppression system.
As a result, there may be a desire to provide containers and methods for containing add/or suppressing a fire in a container.
The invention may seek to satisfy the above-mentioned desire. Although the present invention may obviate the above-mentioned desire, it should be understood that some aspects of the invention might not necessarily obviate it.